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From: Vincent Donnefort <vdonnefort@google.com>
To: maz@kernel.org, oupton@kernel.org, kvmarm@lists.linux.dev,
	 linux-arm-kernel@lists.infradead.org
Cc: joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com,
	 yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org,
	 kernel-team@android.com, fuad.tabba@linux.dev,
	qperret@google.com,  weilin.chang@arm.com,
	Vincent Donnefort <vdonnefort@google.com>,
	stable@vger.kernel.org
Subject: [PATCH v2 1/4] KVM: arm64: Fix MMFR0 TGRAN advertisement for pVMs
Date: Mon, 28 Sep 2026 10:54:50 +0100	[thread overview]
Message-ID: <20260928095454.3255918-2-vdonnefort@google.com> (raw)
In-Reply-To: <20260928095454.3255918-1-vdonnefort@google.com>

Protected VM ID register emulation leaves unlisted fields at 0. This
creates two issues for TGRAN:

  * TGRAN16: 0 means non-implemented. It prevents 16KB protected VMs
    from booting even when the hardware supports it.

  * TGRAN4|TGRAN64: 0 means implemented. This may falsely advertise the
    feature even when the hardware does not support it.

Advertise all the TGRAN fields in pvmid_aa64mmfr0 so that the hardware
support is properly propagated.

Cc: stable@vger.kernel.org
Fixes: 6c30bfb18d0b ("KVM: arm64: Add handlers for protected VM System Registers")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
---
 arch/arm64/kvm/hyp/nvhe/sys_regs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index 8758c6801776..ec469d96516a 100644
--- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -121,6 +121,9 @@ static const struct pvm_ftr_bits pvmid_aa64mmfr0[] = {
 	MAX_FEAT(ID_AA64MMFR0_EL1, SNSMEM, IMP),
 	MAX_FEAT(ID_AA64MMFR0_EL1, BIGENDEL0, IMP),
 	MAX_FEAT(ID_AA64MMFR0_EL1, EXS, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN4, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN16, IMP),
+	MAX_FEAT(ID_AA64MMFR0_EL1, TGRAN64, IMP),
 	FEAT_END
 };
 
-- 
2.56.0.rc1.315.gc6ed9934b7-goog



  reply	other threads:[~2026-09-28  9:55 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-28  9:54 [PATCH v2 0/4] Fix guest_memfd and protected VMs on systems with pages larger than 4K Vincent Donnefort
2026-09-28  9:54 ` Vincent Donnefort [this message]
2026-09-28  9:54 ` [PATCH v2 2/4] KVM: arm64: Pass kvm_s2_fault_desc to fault_supports_stage2_huge_mapping() Vincent Donnefort
2026-09-28  9:54 ` [PATCH v2 3/4] KVM: arm64: Use kvm_s2_fault_vma_info in gmem_abort() Vincent Donnefort
2026-09-28  9:54 ` [PATCH v2 4/4] KVM: arm64: Use kvm_s2_fault_vma_info in pkvm_mem_abort() Vincent Donnefort
2026-10-01 14:24 ` [PATCH v2 0/4] Fix guest_memfd and protected VMs on systems with pages larger than 4K Marc Zyngier

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